Method for manufacturing one-side electrogalvanized steel strip

Abstract

A method for manufacturing a one-side electrogalvanized steel strip, which comprises: continuously causing a steel strip to travel through an electrogalvanizing bath in an electrogalvanizing tank; arranging an electrode plate in the electrogalvanizing bath in the electrogalvanizing tank in parallel to a one-side surface to be electrogalvanized of the steel strip; electrogalvanizing the one-side surface of the steel strip; arranging a spray nozzle toward the other surface not electrogalvanized of the steel strip which has passed through the electrogalvanizing tank; ejecting any one of an aqueous solution containing a weak acid of from 0.1 to 5.0 wt. % and a saturated monovalent alcohol having carbon atoms of up to 5 from the spray nozzle onto the other surface of the steel strip to wet the other surface of the steel strip; arranging a brush roll in close proximity to the spray nozzle on the same side as the spray nozzle; and rotating the brush roll while bringing same into contact with the other surface thus wet of the steel strip to eliminate contamination caused by the deposition of an electrogalvanizing solution on the other surface of the steel strip.

What is claimed is: 
     
       1. A method for manufacturing a one-side electrogalvanized steel strip, which comprises: continuously causing a steel strip to travel through an electrogalvanizing bath in an electrogalvanizing tank; arranging at least one electrode plate in said electrogalvanizing bath in said electrogalvanizing tank in parallel to a one-side surface to be electrogalvanized of said travelling steel strip; causing an electric current to flow between said at least one electrode plate and said travelling steel strip through said electrogalvanizing bath to electrogalvanize said one-side surface of said travelling steel strip; arranging at least one spray nozzle toward the other surface not electrogalvanized of said travelling steel strip which has passed through said galvanizing tank over the entire width of said steel strip; ejecting liquid from said at least one spray nozzle onto said other surface not electrogalvanized of said travelling steel strip to wet said other surface of said travelling steel strip; arranging at least one brush roll in close proximity to said at least one spray nozzle on the same side as said at least one spray nozzle relative to said travelling steel strip, said at least one brush roll having a rotation axis parallel to the width direction of said travelling steel strip and extending over the entire width of said steel strip, said at least one brush roll being in contact with said other surface not electrogalvanized of said travelling steel strip; and rotating said at least one brush roll to eliminate contamination caused by the deposition of an electrogalvanizing solution on said other surface not electrogalvanized of said travelling steel strip;   characterized in that:   said liquid ejected from said at least one spray nozzle is any one of an aqueous solution containing a weak acid within the range of from 0.1 to 5.0 wt. % and a saturated monovalent alcohol solution having a number of carbon atoms of up to 5.   
     
     
       2. The method as claimed in claim 1, characterized in that: said liquid is said aqueous solution of a weak acid selected from the group consisting of oxalic acid, citric acid, malonic acid, and acetic acid.